Solid state light bulb assemblies, e.g. LED or OLED lamps, make use of power converters to convert an input voltage (e.g. derived from the mains supply) into an output voltage for driving the solid state light source. The voltage supply for the light source current control stage should be able to cope with a wide range of voltages at the input. Conventional control solutions suffer from a limited PSRR (power supply rejection ratio) which limits the usable voltage range.